1. Technical Field
The present invention relates to medical image analysis, and more particularly, to a system and method for automatically extracting a bone structure from a three-dimensional (3D) medical image.
2. Discussion of the Related Art
Current three-dimensional (3D) volume rendering techniques such as maximum intensity projection are used by medical practitioners to extract high-intensity structures such as bones from volumetric data acquired during computed tomography (CT) scans. These techniques, however, require manual input to remove a region of interest (ROI) such as a bone structure that obscures vascular structures from such data.
One technique for extracting an ROI from, for example, a stack of slice-based medical image data is to manually mark areas associated with the region on each slice of the image data. This technique, however, is time consuming and sometimes inaccurate, as a medical practitioner must manually mark each area region. Another technique used to extract ROIs is to combine an automatic path detection technique such as Livewire with interpolation. Yet another technique for extracting ROIs is to perform a region growing on an ROI defined by a group of connected blood vessels whose intensity is within a given range.
These techniques, however, do not extract portions of an ROI where, for example, bone structures touch blood vessels due to overlapping intensity ranges. Moreover, to remove such connections time consuming manual corrections to the image data such as the placing of blockers must take place before reprocessing the image.
Although automatic image segmentation techniques have been developed to remove connections between bones and blood vessels, they are not suitable for large amounts of data or high-speed analysis. Accordingly, there is a need for an image analysis technique that can extract unwanted objects from medical image data without manual interaction and that operates at a high speed.